Various systems identify gases using laser light. Some systems include laser light sources that each emits a single wavelength of light. The single wavelength light passes through a sample of the unidentified gas, and the intensity of the single wavelength light is measured. Multiple different lasers can be used to determine the intensities of multiple different wavelengths of light at different times. The intensities can reveal the identity of the gas.
One problem with these types of laser-based systems is the cost and complexity. In order to identify a variety of gases, many different lasers may be needed, which can be expensive and increase the complexity in design and alignment of the systems.
Other systems use a light source that generates many wavelengths of light or a continuum of wavelengths and a filter wheel having many different filters. The different filters selectively transmit (or pass) different wavelengths of light and block other wavelengths from the light generated by the light source. The filter wheel is rotated in a batch manner to move different filters between the light source and the gas at different times. The intensities of the lights passing through the gas are examined to identify the gas.
One problem with both the laser and filter wheel approaches is that these techniques may require some prior knowledge of the gases that are present in a sample. The presence of additional gases can change a baseline of the measured intensities or add to the data and hamper the determination of the gas composition and gas concentrations in the sample. Another approach uses Fourier transform infrared spectroscopy (FTIR) to examine the gas, but this approach is costly, complex, and generally not deployable outside of a laboratory setting.